The present invention relates to a lighting system for providing the driver of a semi tractor-trailer or other large vehicle a reference location of rear trailer wheels relative to a roadway and surrounding structure by projecting a light pattern onto the roadway surface coincident with the rear wheels of the vehicle.
As is commonly known, drivers of semi tractor-trailers often have problems in determining how far to the rear their trailer extends and especially where their rear wheels are located with respect to curbing, corners of buildings and the like. This is due to the fact that the tractor-trailer combination is lengthy, resulting in a depth perception problem and that the driver cannot have a wide angle rear-view mirror mounted within the tractor cab, as do most automobiles. It is crucial, when a driver is attempting to maneuver the tractor-trailer rig in close quarters and when attempting to pass another vehicle on the highway, for the driver to be able to determine the rearward extent of his trailer. The problem is exaggerated at night and during bad weather conditions due to the spray mist that such a large vehicle creates, due to its contact with the wet road. The mist surrounds the vehicle and further limits visibility.
Due to these hazards, it is a common practice within the trucking industry for a passed truck to flash his vehicle headlights at the passing truck, as a sign that it is safe to move back into the same lane. Such a practice is not universal, however, and drivers of automobiles rarely give such signals. This makes it more crucial for the truck driver to have a reference when passing an automobile, especially since this is a more frequent occurrence and more dangerous because the relatively small size of the automobile increases the depth perception problem.
As a consequence, the need exists within the trucking industry for a reliable method of visually indicating to a semi tractor-trailer driver just how far to the rear his trailer extends relative to surrounding vehicles or objects.
It is also important to provide an apparatus for providing a lighted visual spot with the apparatus providing a relatively bright light that is not subject to occlusion by mud or the like thrown rearward by the rear tires.